High-frequency switching transistor and high-frequency circuit

Abstract

A circuit includes first, second, third and fourth terminals, and first and second switches. The first switch switches a first signal from the first terminal to the second terminal or from the first terminal to the fourth terminal. The second switch switches a second signal from the third terminal to the second terminal or from the third terminal to the fourth terminal. The first switch comprises a first switching element with a first high-frequency switching transistor connected between the first terminal and the second terminal, and a second switching element with a second high-frequency switching transistor connected between the first terminal and the fourth terminal. The second switch comprises a third switching element with a third high-frequency transistor connected between the third terminal and the second terminal and comprises a fourth switching element with a fourth high-frequency switching transistor connected between the third terminal and the fourth terminal.

The invention claimed is: 
     
       1. A circuit with a first terminal, a second terminal, a third terminal and a fourth terminal, comprising:
 a first switch, which is formed to switch a first signal from the first terminal to the second terminal or from the first terminal to the fourth terminal; and 
 a second switch, which is formed to switch a second signal from the third terminal to the second terminal or from the third terminal to the fourth terminal, 
 wherein the first switch comprises a first switching element with a first high-frequency switching transistor, which is connected between the first terminal and the second terminal, and a second switching element with a second high-frequency switching transistor, which is connected between the first terminal and the fourth terminal, and 
 wherein the second switch comprises a third switching element with a third high-frequency transistor, which is connected between the third terminal and the second terminal and comprises a fourth switching element with a fourth high-frequency switching transistor, which is connected between the third terminal and the fourth terminal, 
 wherein the first, second, third and fourth high-frequency switching transistors are controllable such that the fourth high-frequency switching transistor is opened when the first high-frequency switching transistor is opened, the fourth high-frequency switching transistor is closed when the first high-frequency switching transistor is closed, the third high-frequency switching transistor is opened when the second high-frequency switching transistor is opened, and the third high-frequency switching transistor is closed when the high-frequency switching transistor is closed; 
 wherein the first, second, third and fourth high-frequency switching transistors comprise: 
 a substrate having a substrate dopant concentration; 
 a barrier region bordering on the substrate, comprising a first conductivity type and having a barrier region dopant concentration, which is higher than the substrate dopant concentration; 
 a source region embedded in the barrier region, comprising a second conductivity type different to the first conductivity type, and having a source region dopant concentration, which is higher than the barrier region dopant concentration; 
 a drain region embedded in the barrier region and disposed offset from the source region, comprising the second conductivity type and having a dopant concentration, which is higher than the barrier region dopant concentration; 
 a channel region disposed between the source region and the drain region, wherein the channel region comprises a subregion of the barrier region; and 
 an insulation region, which covers the channel region and is disposed between the channel region and a gate electrode. 
 
     
     
       2. The circuit according to  claim 1 , wherein the first, second, third and fourth switching elements comprise one series circuit each of several high-frequency switching transistors, comprising:
 a substrate having a substrate dopant concentration; 
 a barrier region bordering on the substrate, comprising a first conductivity type and having a barrier region dopant concentration, which is higher than the substrate dopant concentration; 
 a source region embedded in the barrier region, comprising a second conductivity type different to the first conductivity type, and having a source region dopant concentration, which is higher than the barrier region dopant concentration; 
 a drain region embedded in the barrier region and disposed offset from the source region, comprising the second conductivity type and having a dopant concentration, which is higher than the barrier region dopant concentration; 
 a channel region disposed between the source region and the drain region, wherein the channel region comprises a subregion of the barrier region; and 
 an insulation region, which covers the channel region and is disposed between the channel region and a gate electrode. 
 
     
     
       3. The circuit according to  claim 1 , wherein the first terminal is connectable to a ground potential via a fifth switching element, and wherein the third terminal is connectable to a ground potential via a sixth switching element, wherein each of the fifth and the sixth switching elements comprises one high-frequency switching transistor, comprising:
 a substrate having a substrate dopant concentration; 
 a barrier region bordering on the substrate, comprising a first conductivity type and having a barrier region dopant concentration, which is higher than the substrate dopant concentration; 
 a source region embedded in the barrier region, comprising a second conductivity type different to the first conductivity type, and having a source region dopant concentration, which is higher than the barrier region dopant concentration; 
 a drain region embedded in the barrier region and disposed offset from the source region, comprising the second conductivity type and having a dopant concentration, which is higher than the barrier region dopant concentration; 
 a channel region extending between the source region and the drain region, wherein the channel region comprises a subregion of the barrier region; and 
 an insulation region, which covers the channel region and is disposed between the channel region and a gate electrode, 
 
       and wherein the circuit is formed to control the fifth and sixth switching elements such that when the high-frequency switching transistor of the fifth switching element is closed, the high-frequency switching transistor of the sixth switching element is opened, and that when the high-frequency switching transistor of the fifth switching element is opened, the high-frequency switching transistor of the sixth switching element is closed.